RU2033569C1 - Illuminating unit - Google Patents

Abstract

FIELD: vehicles. SUBSTANCE: device has reflector which shape is either paraboloid or divergent ellipse. Lamp filament is located behind focus and does not have shielding screen between filament and reflector, this results in fact that divergent light beam is reflected from reflector. Lens unit has prism parts which refracts light beams that go through them downwards. This provides desired light beam pattern. EFFECT: increased functional capabilities. 7 cl, 11 dwg

Description

 The invention relates to lamp fixtures and in particular relates to a vehicle headlamp or a fog lamp.

 In vehicle headlights, it is common practice to use a reflector in the form of a paraboloid and to install an incandescent lamp so that the filament giving dipped or oncoming light is located in front of the focal point of the parabolic reflector. This gives a converging ray of light after reflection from the surface of the reflector. Inside the lamp there is a screen located below the filament, which shields the light from the filament, thereby preventing light reflection from most of the lower half of the reflector. Due to the location of the filament in front of the focus, the radiation pattern is upside down, and without such a screen the light would be reflected upward from the bottom of the reflector, blinding the drivers of oncoming vehicles. The screen reduces the overall efficiency of the lamp, as part of the light produced is almost lost.

 Known methods for increasing efficiency using complex forms of the reflector, in which its various parts have different focal lengths. However, in such reflectors, parts of the reflector are usually positioned so that their foci basically coincide, and the dipped filament is located in front of the matching foci. Such complex-shaped reflectors must be performed with great accuracy and step-shaped sections between different sections are used. Such stepped portions can produce unwanted reflections, especially when the reflector surface is varnished, which is usually done to protect the reflective film.

 Another drawback of such reinforcement is that the filament itself must be supported inside the bulb and a support element close to the focus can give images where sharp beam cutoff is required.

 Additionally, for headlights of vehicles, it is necessary to provide for the use of various lamps with different designs of the screen of the filament, depending on the light requirements of the headlights in the country in which the lamp fixtures are designed for use. It also depends on the side of the road on which the vehicle should move. Additionally, lamps of various designs are required for fog lamps or guided floodlights.

 A lamp fixture is proposed that includes a reflector having a focus, means for maintaining the light source in a predetermined position relative to the specified focus, and a transparent lens element located so that the reflected light from the light source passes through it, in which these supporting means are adapted to hold the light source behind focus, there is no screen between the light source and the used reflector surface, and the transparent lens element has one or more prisms that are adapted to measure downward direction of the light rays directed upward after reflection from the upper part of the reflector surface.

 In one design, the transparent lens element has one or more prisms installed to produce an asymmetric cut-off of the radiation pattern in accordance with current ECE lighting requirements for dipped headlights. Such an asymmetric slice has a horizontal portion and an upwardly inclined portion to define a central bend point. This central bend point is used to direct the beam and is precisely defined because the location of the entire light source behind the focus produces a diverging beam.

 In another embodiment, the transparent lens element has one or more prisms to modify the radiation pattern so as to meet US SAE dipped beam requirements.

 You can use lamp fittings with a conventional reflector and complete light source only by changing the design of the transparent lens element. In the case of a transparent lens element for ECE requirements, the headlamp can be modified depending on the direction of movement (right or left) for a specific country with just a side turn over of the single structure of the transparent lens element. By ECE requirements it is necessary to understand that the side of the horizontal slice of the radiation patterns, from where the upward part of the slice extends, depends on the direction of movement in a given country. The lens element can determine the shape of the front surface of the lamp fixture, if the uneven part is located on the inside of the lens element so that the outside is smooth and easy to clean, three lights behind its front glass. In some cases, this is desirable, for example, when the design of the car requires the use of a front glass with a large angle of inclination relative to the vertical, and also it is desirable for ECE headlights for dipped beam where the direction of travel along the road determines the location of the lens element so that the lenses / prisms were on the outside of the glass.

 Since the entire light source is behind the focus of the reflector, a diverging light beam with a relatively even distribution of light on the entire surface of the lens element is obtained, while there is no excessive heating of parts of the transparent lens element. Thus, it is possible to precision compact a transparent lens element made of plastic instead of using a more heat-resistant material, such as glass, known for its intractability to precision compaction. Thus, such a lens element allows you to get a beam with a sharp section of the radiation pattern without using a screen between the light source and the reflector.

 Placing the entire light source behind the focus also means that the legs (which also emit light) used to support the light source are in a position that better fits into the optical structure of the transparent lens element used in this invention.

 The light source usually has the form of a filament on the supporting legs inside a glass bulb, it can be with quartz glass, a halogen type and is removably installed in the lamp holder of the armature. The light source can be a “ray” filament with a so-called “sealed beam” in which the filament without a bulb is mounted on the supporting legs directly in the reflector, which is hermetically sealed after filling with gas (nitrogen) to prevent oxidation of the filament during operation.

 In the proposed lamp fixture, which is designed for low beam, in areas of the transparent lens element that lie above the horizontal medial plane of the lamp, it is preferable to refract light rays in a downward direction with an increase in refraction in an upward direction from the medial plane.

 The invention also relates to lamp fittings, including the specified light source mounted behind the focus and without a screen that prevents the passage of light on the lower part of the reflector. However, the light source is equipped with a conventional screen of the so-called overhead light, which prevents direct light from the lamp from entering the transparent lens element.

The reflector may be in the form of a paraboloid with a more complex shape, for example, the body of rotation of that part of the ellipse that is near the internal focus between the major and minor axes of the ellipse, and rotation is relative to the axis that intersects the ellipse between the specified region and the major axis of the ellipse and which passes through the specified internal focus (hereinafter such a reflector will be called simply "diverging ellipsoid reflector"). The diverging ellipsoid reflector has one internal focal point and an infinite number of external focal points located on a circle in the external focal plane. With a light source located immediately behind the internal focus in a diverging ellipsoid reflector, the light rays from the source that were reflected from the reflector are diverging. The angle between the indicated major axis of the ellipse and the axis of rotation of the specified area can be up to 1 ^about and is usually about 0.5 ^about . The focal length of the ellipse can be such that the external focal points are located at a distance of 25 m from the lens element so that the reflected light is focused on the plane in which the necessary photometric measurements are made in accordance with the ECE requirements for the low-beam emission diagram. For lamps that must meet the requirements, the focal length of the ellipse is selected so that the external focal points are located at a distance from the lens element that meets these requirements.

 It is also possible to use more than one reflector and an associated light source of the indicated type so that each reflector and its associated light source give the corresponding part of the overall radiation pattern that is required from the lamp fixture. Such a design is considered advantageous in that where the design of a car equipped with lamp fittings does not allow to obtain the desired radiation pattern from a single reflector with a light source.

 Figure 1 shows the position of the filament of the lamp in the reflector of the proposed lamp fittings; in FIG. 2 radial images of the filament; figure 3 schematically shows the effect of using a transparent lens element, which is part of a lamp fixture; figure 4 lens element, front view; figure 5 the total distribution of light from the lower half of the reflector after passing through the lower half of the lens element; in Fig.6, the overall slope down and the distribution of light from the upper part of the reflector after passing through the upper part of the transparent lens element; 7, a divergent ellipsoid reflector; on Fig part of the headlight assembly; Fig.9 lens element used in the lamp fixtures of Fig.8, front view; figure 10 schematically shows a view of another form of the lens element for use with the reflector of figure 7 to obtain a radiation pattern that meets the requirements of AE USA for the lighting equipment of cars; figure 11 shows the participation of parts of the lens element of figure 10 in the final radiation diagram.

 Tube fixtures (see FIGS. 1-3) are a car headlight that is designed to create a radiation pattern that meets ECE requirements in right-hand traffic countries. Tube fittings include a plate reflector 10 made of thermosetting plastic molded under pressure. The body 10 has an internal paraboloidal reflective surface 12 with a focus 14 and an optical axis 16 located in the horizontal medial plane of the body 10. The body 10 has a front hole 18 and a central rear hole 20 with a collar 22 for the lamp to enter. A lamp with a filament 24 enters the collar 22 so that its axis is parallel to the optical axis of the armature 16, and the front end falls into focus 14. The sleeve forms part of the lamp holder, and the bracket holding the lamp has the usual form and holds the lamp so that its flange is pressed against the inner flange of the reflector sleeve. The lamp is equipped with an overhead light screen, the size of which is limited so that the reflected light from the filament 24 does not pass into the front opening of the reflector 18. However, unlike conventional headlight lamps, there is no screen below the thread 24. As a result of this, the light from the filament 24 enters the lower part of the reflective surface of the reflector 12. The lower part refers to the part located under the horizontal median plane of the body 10.

 The light from the filament 24, which enters the paraboloid reflecting surface 12, passes through the front hole 18 and gives a diverging round beam in which the images of the filament are radially arranged. In FIG. 2 shows a typically large image of the filament 26 due to reflection from a portion of the reflective surface 12 close to the filament 24, and a small image of the filament 28, which is obtained by reflection from a part of the reflective surface 12 located near the front hole 18, i.e. relatively far from the filament 24.

 The lamp fitting of FIG. 3 comprises a transparent lens element 30, which is located in front of the front opening 18 of the reflector. In this embodiment, the lens element 30 forms a transparent front headlamp cover and is glued to the headlamp housing (not shown), in which the reflector body 10 is mounted with the possibility of adjusting the headlights. The transparent lens element 30 is extruded from a suitable transparent synthetic material, for example polycarbonate resin. In an alternative embodiment, the lens element 30 is implemented as a separate product installed in the headlight housing, which is then closed by a separate glass cover.

Figure 4 shows the element 30 in the form of a rectangular plate. In practice, the vertical side edges of the element 30 will be rounded in accordance with the curvature of the front hole 18, which is generally rectangular in shape with rounded side edges. The lens element 30 has sections AC. All parts from A to C lie above the horizontal median plane of the headlamp, this plane is shown by the dashed line PP in figure 4. If you look at the front of the reinforcement, part A lies above part B, which is located above the greater half of section C. Parts A and B and that part of section C, which is located to the right of the vertical plane in which the optical axis 16 is located, are horizontal. Part of the region C, which is located to the left of the specified vertical plane, is inclined upward at an angle of about 15 ^about . Parts A, B and C are prismatic sections that refract the light passing through them down. The amount of refraction increases from the horizontal median plane PP in the upward direction. Part A refracts light at a larger angle than part B, which refracts light at a larger angle than part C. As a result, the light that passes through parts A, B and C is refracted down below the horizontal median plane of the reflector.

 The resulting radiation pattern from part A, B and C is shown in FIG. 6, where it is seen that the part of the light that passed through section C is just below the critical upper section 32 of the radiation pattern, while the parts of the light flux that passed through sections B and A are below it. The prismatic section C has practically no horizontal curvature and therefore does not produce horizontal divergences. The upper edge 22 of the radiation pattern has a horizontal section 34 and an inclined section 36 extending from the end of the section 34. Such sections 34 and 36 are a necessary part of the desired radiation pattern in accordance with current ECE requirements.

The lens element 30 (see FIG. 4) has a horizontal portion E, which extends horizontally and is made substantially even, i.e. it is not prismatic and gives a very small horizontal divergence. A portion of the final radiation pattern resulting from the passage of light through section E is shown by the corresponding section E in FIG. 5. It can be seen that this section defines an important horizontal section 34. As can be seen from figure 4, section E with the upper edge adjacent to the horizontal median plane PP. Plot E ends on the vertical median plane of the reflector. Section D of the lens element 30 with the lower edge is aligned with section E, while the upper edge is inclined up and to the left of the optical axis 16 at an angle of about 16 ^about to the horizon. Like section E, section D practically does not refract and determines the upwardly directed section 36 of the radiation pattern and an important part of the beam immediately below section 36.

Section F of the lens element 30 is located to the left of the vertical median plane of the reflector body under section D and also practically does not refract. The lower edge of section F is inclined down and to the left of the vertical median plane at an angle of about 10 ^degrees to the horizontal. This portion gives the beam portion F of the final radiation pattern (see FIG. 5).

 Region C has a horizontal curvature of the lenses to obtain horizontal beam expansion.

 The whole summary beam pattern under the action of a combination of these diagrams is shown in Figs. 5 and 6. The diagrams in Figs. 5 and 6 are obtained at a distance of 25 m from the lamp, if you look at the beam, it is at this distance that the luminous flux is measured to verify that it satisfies whether the pattern of the ECE standard.

. Участок R является соседним с внутренним фокусом 1 и находится на расстоянии от большой и малой осей эллипса М и

соответственно на эллипсе S. Вращение производится вокруг оси Т, которая пересекает эллипс S между указанной областью R и большой осью М, которая проходит через указанный внутренний фокус 1.7 shows a diverging ellipsoid reflector, which is obtained by rotating the portion R of the ellipse part (only part shown) with internal focus 1, external focus 0, major axis M and minor axis

. Section R is adjacent to the inner focus 1 and is located at a distance from the major and minor axes of the ellipse M and

respectively, on the ellipse S. The rotation is made around the axis T, which intersects the ellipse S between the specified region R and the large axis M, which passes through the specified internal focus 1.

The angle α between the major axis M of the ellipse and the axis of rotation T of the portion R in this design is 1/2 ^about . The distance from the internal focus the internal focal length of the ellipse is 29-32 mm, while the distance from the external focus is 25 m from the lens element in the assembled lamp fixture. The resulting diverging ellipsoid reflector 10 (see Fig. 8) has one internal focus 14 and an infinite number of external foci arranged in a circle in the external focal plane.

FIG. 8 also shows typical images of the filament 24a, 24b, 24c, when the filament 24 is located immediately behind the internal focus 14 after reflection from the reflector 10. Typical images of the filament 24a-24c pass through the parts AC of the lens element 30, respectively, and together with others images of the filament that pass through other parts of the lens element 30 create an asymmetric radiation pattern similar to that shown in FIG. 5 and 6. In this design, sections A, B and C have progressive prisms set to refract the beam down 1/2 ^o + (1/2 3 1/2 ^o ) for section A, 1/2 ^o + (2 1 / 2 ^o + 5 1/2 ^o ) for section B and 1/2 ^o + (3 4 1/2 ^o 7 ^o ) for section C. Other sections of the lens element 30 in Figs. 8 and 9 are similar to the sections DG of the lens element in figure 4.

 In FIG. 10 and 11 show a transparent lens element for use with the diverging ellipsoid reflector of FIGS. 7 and 8. In this embodiment, portions A-C of the lens element 30 are formed by combined prisms and lenses that refract light rays downward and expand them horizontally so that it coincided with the light that passed through sections G, which contain lenses only for horizontal expansion of the beam. Section D has a weak lens to slightly concentrate the beam in the center. Section E refracts the transmitted rays slightly downward, so that the light coincides with the beam passing through section F, which slightly expands the beam. Sites AE are located above the horizontal median plane of the reflector 10, in which the T axis is located (see Fig. 7). The radiation pattern shown in FIG. 11 should meet the requirements of the US SAE dipped beam standard.

Claims (7)

 1. LAMP FITTINGS, comprising a reflector having a focus, means for mounting a light source in a predetermined position relative to the focus, and a transparent lens element mounted so that light from the source passes through it, characterized in that, in order to increase the efficiency of the lamp, the mounting means adapted to fasten the light source behind the focus without shielding between the light source and the reflector, while the transparent lens element is provided with at least one prism for directing the light reflected upward from the top st part reflector downwards.  2. The armature according to claim 1, characterized in that said prisms located on a transparent lens element are made to form a radiation pattern having an asymmetric slice, in accordance with the current ECE requirements for the installation of dipped headlights.  3. The fittings according to claim 1, characterized in that the prisms are made to modify the radiation pattern in accordance with the requirements of AE USA for the installation of dipped headlights.  4. The fittings according to claim 1, characterized in that the prisms are made to obtain a fog beam.  5. The reinforcement according to claim 1, characterized in that said prisms, which are located above the horizontal median plane of the lamp, are made to refract the light passing through them downward, the magnitude of the refraction progressively increasing upward from the horizontal median plane.  6. The fittings according to claims 1 to 5, characterized in that the reflector is made paraboloid.  7. The fixture according to claims 1 to 7, characterized in that the light source, which is installed behind the focus without shielding, is made to prevent light from entering the lower part of the reflector, while the fixture is equipped with a screen to prevent the non-reflected light from coming out directly from the lamp fixture through a transparent lens element.

Images